Thermal oxidizers, utilities

The reaction presented above is utilized to leach lead sulfate obtained by thermal oxidation of a mixture of sulfide minerals. The rate of dissolution chemically with a reagent in an... 

Both concentrated and dilute waste were sent to a pair of John Zink thermal oxidizers equipped with adjustable venturi scrubbers for removal of particulates prior to stack discharge. Water process waste originating primarily from fermentation sectors was sent to the Carver-Greenfield evaporation system. The evaporator utilized a multistep oil dehydration process and was equipped with a centrifuge, waste heat boiler, and a venturi scrubber. The Clinton Laboratory reported an overall BOD and COD reduction of 90 and 99%, respectively, depending upon the configuration used. 

One of the metrology issues with the STI process is that the process utilizes three layers of different materials (1) thin thermal oxide (less than 200 A), (2) nitride (approximately 1500 A), and (3) the TEOS oxide above the active regions (see Fig. 7). Ideally, the CMP process polishes the TEOS oxide and stops at the nitride. In reality, after the polish, either a very thin residual TEOS oxide is present or the TEOS is completely gone and the nitride thickness is being measured. This poses some problems in the setup... 

A number of vendors offer SNCR technology based on either ammonia or urea. Exxon Mobil Thermal DeNO (TDN) technology is a common SNCR process applied to FCC units. The technology is licensed exclusively to Hamon Research-Cottrell Inc., and has been utilized to achieve postcombustion NO reduction in CO furnaces, thermal oxidizers, overhead regenerators, and power boilers. Thermal... 

Information on rental costs for EPFs Venturi Thermal Oxidizer is given in Table 1. Information on utility costs of various venturi models is given in Table 2. 

Risen and Wang developed a method and compositions for producing microlenses and optical filters. According to their method, carboxylated silicone or polysilicone precursor composition is applied to the surface of a substrate to form a precursor droplet, which is thermally oxidized to form a microlens. The substrates utilized were silica, silicates, borosilicate glasses, and silicones. The precursors, which are present in concentrated solutions, are viscous fluids which are used to form microdroplet precursors. A solvent such as ethanol or acetone is added to the precursors to modify and control their flow and surface tension properties, to facihtate the formation of spherical shape of the precursor on substrates. The precursor droplet volume is 4-600 picoliters and forms a droplet of 20 to 1000 micrometers in diameter. 

Zeolites have also proven applicable for removal of nitrogen oxides (NO ) from wet nitric acid plant tail gas (59) by the UOP PURASIV N process (54). The removal of NO from flue gases can also be accomplished by adsorption. The Unitaka process utilizes activated carbon with a catalyst for reaction of NO, with ammonia, and activated carbon has been used to convert NO to N02, which is removed by scrubbing (58). Mercury is another pollutant that can be removed and recovered by TSA. Activated carbon impregnated with elemental sulfur is effective for removing Hg vapor from air and other gas streams the Hg can be recovered by ex situ thermal oxidation in a retort (60). The UOP PURASIV Hg process recovers Hg from clilor-alkali plant vent streams using more conventional TSA regeneration (54). Mordenite and clinoptilolite zeolites are used to remove HQ from Q2, clilorinated hydrocarbons, and reformer catalyst gas streams (61). Activated aluminas are also used for such applications, and for the adsorption of fluorine and boron—fluorine compounds from alkylation (qv) processes (50). 

Both polymers have excellent hydrolytic stability—one because it is a polyether and the other because it sterically hinders hydrolytic action. The polycarbonate, like the polyether, is reported to be compatible with polystyrene. The high T would suggest dimensional stability and utility at very high temperatures, but thermal-oxidative limitations will probably favor blend applications at moderately high continuous-use temperatures. 

Ultimately, fonnation of parts per million (ppm) levels of ethylene was corroborated by very carefully controlled laboratory experiments that duplicated plant timehnes and reahstic temperature swings. Eventually, the analytical data were utilized to justify the connection of a thermal oxidizer to deal with the ethylene emissions. Needless to say, if this issue had not been resolved successfully, the plant in Connecticut would have found it difficult to continue manufacturing this compound. 

Whenever possible, more rapid turnaround time, the absence of load locks, the reduced maintenance cost associated with the avoidance of vacuum systems, and the ease of incorporation into continuous processing systems, all combine to make atmospheric pressure chemical vapor deposition an attractive technique. In general, removal of reaction co-products is accomplished by utilization of a large excess of carrier gas (typically argon or nitrogen). Additionally, it may be noted that the thermal oxidation... 

The objective was not only to utilize the calorific values of these by-products or residues but also to reuse them chemically. This was achieved by thermal oxidation (incineration) with simultaneous neutralization to give potassium halides that are subsequently dissolved in water. The salt solution obtained is used for the recovery of potassium bromide, potassium fluoride, and potassium chloride as raw materials. 

Addition polyimides having reactive end groups (mostly aliphatic in character) show reduced thermal oxidative stability. These end groups are utilized to overcome the processing problems associated with condensation polyimides. 

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